People use containers for holding beverages or food during every conceivable activity throughout the day, including driving, bike-riding, running, working, etc. In some situations, people want to hold hot or cold beverages or food in these containers. Some of the activities may require the container to be robust and transportable so that some materials are better suited for use than others for a given activity.
For example, ceramic mugs can hold hot beverages, but the mugs do not keep the beverage hot very long. Also, the mugs do not resist impact and are easily broken. As a consequence, ceramic mugs are not easily transportable. Of course, plastic containers can be used, but the drawbacks of plastic are well known. Stainless steel containers are also used to hold beverages, and double-walled, vacuum-insulated stainless steel containers can be used to hold hot and cold beverages or food. When holding hot beverages or food, the stainless steel may impart a metallic taste to the beverage or food and may change its flavor to an extent.
Aluminum bottles can be used to hold beverages. However, the aluminum bottle does not retain heat for use with hot beverages. Also, the aluminum of the bottle can have an odor that negatively impacts the taste of the beverage, especially when hot. To combat the negative taste of the aluminum, aluminum water bottles are available that use an epoxy on the inside of a single-wall aluminum bottle. Unfortunately, the aluminum bottle with epoxy coating cannot keep cold beverages cold and cannot be used for hot beverages (coffee, tea, hot water, etc.) because they will burn the user's hand.
It is recognized that a double-walled, vacuum-insulated container made of stainless steel can have problems when the inside of the container is treated only with electrolysis. It is also recognized that such a container made of metal can have problems when the inside of the container is treated only with an epoxy or resin. For instance, Japanese Patent JP3390349 notes that a fluoro-resin coated on the inside of such a metal container is porous, making the coating easily damaged and stained. Additionally, if the application temperature of the fluororesin (e.g., perfluoroalkoxy copolymer resin (PFA)) is higher than the melting temperature of sealing material that seals an exhaust port for the vacuum formation, then use of the fluororesin is a problem as it becomes impossible to hold the vacuum. Flouroresins can have cure temperatures of as high as 370° C. for PTFE and PFA.
For this reason, it is proposed in Chinese Patent document CN202208422 to Guang Hu et al. to coat the inside of the double-walled, vacuum-insulated container with a ceramic coating with a thickness between 15-60 microns, and preferably 20-30 microns.
As an example of how a ceramic coating is formed on such a container, Japanese Patent document JPH08338 discloses a double-walled, vacuum-insulated container having a film of a ceramic material mixed with antibacterial agent applied to the inside of the container. To form the container, an inner body has the ceramic coating with the antimicrobial agent applied to the inner surface. The coating film is heated for about 20-min. at around 120° C. Aluminum foil is arranged outside the inner body, and an outer body 9 is jointed around the inner body at a seam. A tip pipe on the outer body is used to pull a vacuum in the space between the inner and outer bodies, and the tip pipe is sealed. Finally, a base is attached to the bottom of the outside body to cover the tip pipe.
Another example of coating the inside such a double-walled, vacuum insulated container is disclosed in Japanese Patent document JP3390349, which discloses coating inside the container with porcelain enamel, ceramic, or metal plating. For each of these coatings, manufacture of the container involves coating the inside of the container and then evacuating the space in the container to create the vacuum. Another Japanese Patent document JP2002080075 merely contemplates using a ceramic coating inside the vacuum space of a double-walled container.
As can be seen, a container of suitable material is desired that can be used with hot and cold beverages, food, or the like and can avoid negatively impacting the taste or odor of the contents, while being durable. Conventional wisdom has solved this by applying a coating, such as a ceramic coating, inside a double-walled container and then pulling a vacuum on the container. Although containers manufactured this way may be effective and useful, what is needed is a container that is even more versatile.
The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.